[Analysis for four isomers of resveratrol in red wine by high performance liquid chromatography]

Red wine was treated by hydrolysis with beta-glucosidase, so the piceids in it were converted to resveratrols. The contents of cis- and trans-resveratrols before and after hydrolysis were determined by high performance liquid chromatography, thereby the contents of the four isomers of resveratrol in the red wine can be calculated. The analysis was performed on a Symmetry C18 column (3.9 mm i. d. x 150 mm) with a mixture of ethanol and 0.05% acetic acid solution (23:77, v/v) as the mobile phase at a flow rate of 1.0 mL/min and with UV detection at 306 nm. Results show that there was a good linear relationship (r > 0.999) for all the four isomers of resveratrol in the range of 0.2 - 50.0 mg/L. The detection limits of cis- and trans-resveratrol and the corresponding piceid isomers were 0.81, 1.20, 0.40 and 0.46 ng, respectively. The recovery of resveratrol was more than 98%. Relative standard deviations (RSDs) (n = 5) were from 0.5% to 8.5%. The ranges of concentration of total resveratrol were 0.84 - 7.33 mg/L in eleven dry red wines and 0.12 - 6.00 mg/L in three grape juices. The method is convenient, and there are good precision and repeatability. The method is applicable for the analysis of four isomers of resveratrol in red wines and grape juices.